I'm wanting to start a campaign, let my players create their own characters, and go from there, but I was wondering if you guys thought the free adventure on the website would be a good intro into the setting for people that don't know it well. It's "How I learned to stop worrying and love the bomb".

A) The pre-generated characters for that are all Seasoned rank. This indicates that it is a dangerous adventure.
B) The foes are very dangerous, especially for players unaware of the tendency of all things Combine to explode.
C) While fun, that adventure is considered non-canonical. That's not generally a problem.
D) It seems to be set before the Harvest.

It will give them lots of information about the setting, but they might not survive the learning._________________"Got a problem? I've got the solution: Rocket Launcher."
"Not against a Servitor."
"... We're all gonna die."

Also at the end of the adventure it seems they're given a semi. How would that best be handled? I suppose if they wanted to be a roving band of do-gooders then it could give them a means to do so, while carrying their things and giving them shelter...

As a semi truck. There are stats in HOE Reloaded.
Remember, vehicles have to be maintained, fueled, repaired, protected from theft, and are generally limited to roadways. So, while it's a potentially useful tool, the truck has limited use for a roving band of heroes._________________"Got a problem? I've got the solution: Rocket Launcher."
"Not against a Servitor."
"... We're all gonna die."